<!DOCTYPE html>

<head>
    <link rel="help" href="https://github.com/servo/servo/issues/36971">
    <meta name="assert" content="Using variables in xpath expression should not crash.">
</head>
<body>
    <script>
      // The exact behaviour here is not defined. Firefox throws an error, Chrome doesn't.
      document.evaluate("$foo", document.createElement("div"));
    </script>
</body>
